Bicycle is an open, two wheeled vehicle popular in many countries of the world, and used for pleasure riding, light delivery, racing, and in many areas as a major means of transport. Although the bicycle is by definition a two-wheeler, there are other forms with multiple wheels and seats: tandems for two persons, triplets for three persons, quadruplets for four persons, quintuplets for five persons . . . etc. Recently, a so-called collapsible bicycle has been developed to enhance the mobility thereof, but it is too heavy and inconvenient to fold.
It is, therefore, an object of the present invention to provide a collapsible bicycle which may obviate and mitigate the above-mentioned drawbacks.